void DecayConfigPythia8() {
        // Create a new external decayer instance
        TPythia8Decayer* decayer = new TPythia8Decayer();

        // Create a new TPythia8 instance
        TPythia8* pythia8 = TPythia8::Instance();

        TVirtualMC::GetMC()->SetExternalDecayer(decayer);

        const Int_t npartnf = 9;
        Int_t pdgnf[npartnf] = {13,-13,211,-211,321,-321,130, 3312, 443};
        for ( Int_t ipartnf = 0; ipartnf < npartnf; ipartnf++ ) {
          Int_t ipdg = pdgnf[ipartnf];
          TVirtualMC::GetMC()->SetUserDecay(ipdg);// Force the decay to be done w/external decayer
        }

        decayer->Init();

}

void DecayConfig() {
  DecayConfigPythia8(); 
}

